title: Metastasis to the thyroid gland: report of a large series from the Mayo Clinic.
abstract: OBJECTIVE
  Metastases to the thyroid gland are not as unusual as previously believed. This study reports the largest number of patients with metastatic disease of the thyroid to date, confirms the accuracy of fine-needle aspiration (FNA) in diagnosing metastasis, and reviews the incidence and management through our institutional experience.
  
  
  METHODS
  This study entailed review of all thyroid FNAs performed at Mayo Clinic, Rochester during the period 1980 to 2010 and identified 97 patients with a metastatic solid neoplasm of the thyroid gland.
  
  
  RESULTS
  Frequent primary tumor sites included kidney (22%), lung (22%), and head and neck (12%). The median age at discovery of thyroid metastasis was 63 years. The time from diagnosis of primary tumor to metastasis to the thyroid gland was most considerable for renal cell carcinoma (mean 113 mo). Forty-one patients underwent thyroid resection with an average tumor size of 3 cm. Median survival in all patients with metastases was 20 months (range, 1 to 228 mo). Patients who underwent thyroid resection had a median survival of 30 months (range, 3 to 171 mo), whereas survival in patients without thyroid surgery was 12 months (range, 1 to 228 mo, log-rank test P=0.09).
  
  
  CONCLUSIONS
  Our experience over the last 30 years confirms that FNA remains a sensitive and specific method to detect metastases to the thyroid. In any patient with a history of a malignancy, a new thyroid mass should be promptly evaluated for recurrent malignancy as early diagnosis and surgical resection resulted in a nonstatistically significant increased median survival.
authors.affiliation: Departments of *General Internal Medicine †Internal Medicine, Division of Endocrinology §Anatomic Pathology, Mayo Clinic, Rochester, MN ‡Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, OH.
authors.forename: Livia
authors.initials: L
authors.lastname: Hegerova
authors.forename: Marcio L
authors.initials: ML
authors.lastname: Griebeler
authors.forename: Jordan P
authors.initials: JP
authors.lastname: Reynolds
authors.forename: Michael R
authors.initials: MR
authors.lastname: Henry
authors.forename: Hossein
authors.initials: H
authors.lastname: Gharib
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis / Q000556:secondary* / Q000628:therapy; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044963:Biopsy, Fine-Needle; D001943:Breast Neoplasms / Q000473:pathology; D002277:Carcinoma / Q000175:diagnosis / Q000556:secondary / Q000628:therapy; D002292:Carcinoma, Renal Cell / Q000175:diagnosis / Q000556:secondary* / Q000628:therapy; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000556:secondary* / Q000628:therapy; D017024:Chemotherapy, Adjuvant; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006258:Head and Neck Neoplasms / Q000473:pathology*; D006801:Humans; D053208:Kaplan-Meier Estimate; D007680:Kidney Neoplasms / Q000473:pathology*; D008175:Lung Neoplasms / Q000473:pathology*; D008297:Male; D008545:Melanoma / Q000175:diagnosis / Q000556:secondary / Q000628:therapy; D008875:Middle Aged; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000473:pathology; D015996:Survival Rate; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000556:secondary* / Q000628:therapy; D013965:Thyroidectomy; D055815:Young Adult